Vehicle Audio Control Using Wheel Acceleration for Road Noise Masking
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Solution Overview
Problem
Existing vehicle noise control systems struggle to effectively manage road noise generated between wheels and the ground contact surface, as noise absorption by suspension makes it difficult to directly observe and control the noise source.
Innovation Solution
A vehicle control method that uses a wheel speed sensor to measure angular velocity and acceleration, determining noise levels by analyzing variance and adjusting the sound generation device's volume to match noise conditions, thereby enhancing driver comfort and reducing noise disturbance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the acceleration sensor is positioned on the vehicle body side above the suspension, then the vehicle body noise can be detected, but the road noise source cannot be directly observed due to suspension absorption
Solution Approach 1:
The patent introduces wheel speed sensors as intermediary devices that indirectly measure road noise characteristics through wheel rotation parameters. The angular velocity and angular acceleration derived from wheel speed serve as mediators to infer road noise levels without directly placing sensors at the noise source, thus resolving the contradiction between detection accuracy and measurement accessibility.
2Object-affected harmful factors
If the sound generation device volume is increased to mask road noise, then driver comfort improves, but energy consumption increases
Solution Approach 1:
The patent dynamically adjusts the sound generation device volume based on real-time road noise conditions detected through wheel speed analysis. By making the volume control adaptive rather than static, the system provides necessary noise masking only when road noise exceeds thresholds, thereby improving driver comfort while minimizing unnecessary energy consumption during low-noise periods.
Solution Approach 2:
The system implements feedback control by continuously monitoring wheel speed, calculating angular acceleration, comparing it with threshold values, and adjusting sound generation device volume accordingly. This closed-loop feedback mechanism ensures energy is consumed only when necessary to maintain driver comfort, resolving the contradiction between comfort provision and energy efficiency.
3Power
If the engine output is continuously increased to maintain power availability, then vehicle performance improves, but fuel consumption increases
Solution Approach 1:
The patent employs periodic evaluation of road noise conditions through intermittent analysis of wheel speed variance, enabling the engine control to operate in discrete high-power and low-power states. Instead of maintaining continuously high engine output, the system periodically assesses whether increased power is necessary based on current road noise levels, thus improving vehicle performance when needed while reducing fuel consumption during normal operating conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively manages noise levels by increasing or decreasing the sound generation device's volume based on noise conditions, improving occupant comfort and operational efficiency while maintaining quiet in the vehicle cabin.
Implementation Method 1
a wheel speed sensor to measure an angular velocity of the wheel
Implementation Method 2
angular acceleration obtained by differentiating the angular velocity
Implementation Method 3
a controller to calculate a variance of the angular acceleration
Implementation Method 4
controls the sound generation device so as to increase or decrease a volume of sound generated by the sound generation device
Data Source
Figure 1
Figure 2
Figure 3(A1)~3(B3)
AI summary
By the vehicle control method, in a vehicle provided with a wheel, a sensor that acquires rotation speed of the wheel, and a sound generation device that generates sound as the sound generation device is driven, the angular acceleration of wheel is obtained from the rotation speed acquired by a sensor, and a sound generation device is controlled such that the generated sound becomes louder when conditions are met. Cases in which the angular acceleration is high are included in the conditions.